CODEWITHSUNDEEP
javaspringhibernatejpa
milanHrabos
milanHrabos

Reputation: 1965

How to enable hibernate to set manually primary key?

Having these entity:

@Entity
@Data
@Builder
public class User {
    @Id
    private int id;
    private String name;
}

If i try to set the id:

@Bean
    CommandLineRunner dataLoader(UserRepository userRepo){
        return new CommandLineRunner() {
            @Override
            public void run(String... args) throws Exception {
                User u = User.builder()
                        .id(1)
                        .name("First User")
                        .build();
                userRepo.save(u);
            }
        };
    }

I got

java.lang.IllegalStateException: Failed to execute CommandLineRunner
    at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:794) ~[spring-boot-2.5.3.jar:2.5.3]
    at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:775) ~[spring-boot-2.5.3.jar:2.5.3]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:345) ~[spring-boot-2.5.3.jar:2.5.3]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1343) ~[spring-boot-2.5.3.jar:2.5.3]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1332) ~[spring-boot-2.5.3.jar:2.5.3]
    at com.example.demo.DemoApplication.main(DemoApplication.java:16) ~[classes/:na]
Caused by: org.springframework.orm.jpa.JpaSystemException: No default constructor for entity:  : com.example.demo.domain.User; nested exception is org.hibernate.InstantiationException: No default constructor for entity:  : com.example.demo.domain.User
...

If i don't set the id, then no problem. So how do I can set the primary manually?

Upvotes: 0

Views: 889

Answers (1)

Simon Martinelli
Simon Martinelli

Reputation: 36103

In General: You sholdn't use @Data with Entities because the generated equals/hashCode and toString can lead to StackOverflowError if you have bi-directional entities.

Coming back to your question JPA needs a default constructor (no args constructor)

So I would recommend this:

@Entity
@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class User {
    @Id
    private int id;
    private String name;
}

Upvotes: 2

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